Broaching tool



YPatented July 15, 1930 Unire starts LOWELL oyBLOIvrsTnoi/r, on DETROIT, MICHIGAN, AssIGNoR To FEDERAL MOGUL con- IORA'IION, or Dinners, MIOIIIGAN, A oonIeonATIoN on' MICHIGAN BROAOHING TOOL j Application. filedV July 18,

This invention relates to `an -improved breaching tool, particularly adapted for worl; upon what are known as half bearings or split shells, and has for its object an improved s organization of parts which, whether integral in the first instance, or in a built-up form, as will be hereinafter described, em- 1bodies a high degree of possible accuracy of out and, in one form, a possibility of modification or slight adjustment of the parts to provide what 1s known as a relief cut in thebroaching of the half bearing.`

In the drawings z Figure l is a side elevational view of thesimpler form of my improved broaching tool. Figure 2 is a side sectional elevational view showing the cutter members in place.

Figure 3 is a cross-sectional view taken along the line 3 8 ofv Figure 2.

Figure e' is an elevational view of the relief cutter member taken at right angles to' the position of the tool illustrated in Figures l and 2. t j n Figure 5 is a side elevational viewof a breaching tool with this relief cutter 'shown in position therein. v

Figure 6 is a cross-sectional elevational Y view of the relief cutter itself and ofa half in the first instance, that is, machined from a Y single piece of steel, or maybe built up from various accurately aligned parts. `It is pro-` vided with stops B, against which high steel broaching elements l(l may be fitted, these latter being held in position by threaded collars D which engage over complementarilyv threaded portions Dlon thearbor A. At E is shown in cross section the whole of the half bearing, whose surface is adapted to be` broachingly engaged by the members Gas the broaching tool is forced axially lengthwise of the bearing, when the latter has been clamped in asuitable holding block L, accuratelypo- 1927. senarNo. 206,532. I

sitioned with referenceto the path oftravel of the broaching tool. The action o'fthis type of broaching'members with reference to the half bearing is further brought outin cross sectional Figure 3, wherethe outer surface of the half bearing and its broached inner surface, ,the broaching surfaces of the tools C, and the Ybroaching-tool asa whole are all absolutely coaxial.`l`

.lt often happens, however, .that an addi?V tional, almost infinitesimal Vout or broaching olf of the concaved surface of the half bearing is desiredrimmediately adjacent its 'straight edge portions, in order to provide .for very slight inbending of the halfbearing shell in a subsequent shop operation not necessary to here reviewinV detail. To this end, I provide on the broaching arbor an additionallv t 'breaching' element `or relief vcutter F, which 1 comes into action after the cutters C have iin- *eg' airis ished their work. As brought out inFigures V et and particularly, this reliefl cutter F- is slightly adjustable relatively to the axis of the arbor1 A as a whole by means of the screws or adjusting stops G, whereby it may be rendered eccentric'relative to the arbor A.k It

may thus be, thrown so that its cutting 'surface only touches the inner surfaces of the bearing shell j ustinside of itsstraight edges, and thearbor. F-being of suiiiciently greater diameterL than the elements C which have already performed their work, acts to make a slightjcut'onreach side of the bearing shell whichl havegindicatedat H inFigure 6.

^' Actually this is of farsmallerv degree relatively tol theproportions of the bearing shell than is here shown, butv I have exaggeratedV the illustration for the sake of clearness.

Both theordinary fbroaching operation effected by themembers C'and this'relief cut upon the selected portions of the interior surface of the half bearing E canthus be peri the completely ,circularv breaching tool is in active service. Itisan additional advantage of my Improved constructlon thatwhenever "the initially active half of thebroaching elements becomeworn orV otherwise impaired by the breaching arbor it and it-s other supentirely new set ofk breaching surfaces thus provided without disassembling the mechanism, other than readjustment of the relief cutter to a position diametrically opposite the axial center to that which'it first occupied and of course te the same radial distance therefrom.

Vhat I claim is:

l. A built-up;breaching tool, having, in combination with a supporting arbor, a plurality of axially aligned `parts of variant diameter positioned thereon in initialV coaxial alignment whereby a plurality of longitudinally spaced cutting surfaces are provided, oney of which is capable of selective v axial displacementto minute dimensional specifications, whereby the net cutting` effect of the several active surfaces` when the tool is moved axially lengthwise, is al component of their individual peripheral contours.

2. A breaching tool comprising a carrying arbor, and a plurality of circular cutter elements spacedly positioned thereon and individually removable therefrom, one of said cutter elements being capable of adjustment to axially eccentric position relatively to the other cutter elements and to the arbor.

3. In al breaching tool, in combination with a carrying arbor, plain circular cutter members spacedly positioned thereon, and a relief vcircular cutter member also carried thereby and capable of adjustment to various positions of eccentricity relatively to the axis of the arbor and of the plain cutter members.

4. In a breaching tool, the combination,

' with a carrying arbor, of circular cutter ele- Cil ments spacedly positioned thereon, and

means incorporated with one of said cutter elements whereby it may beadjustedto various positions ofeccentricity relatively to the axis of the carrying arbor and of the other cutter elements. A i i 5. In a breaching tool, in combination with a carrying arbor, removable cutter members spacedly engaging thereabout in position of continuous Vcoaxality relatively to said carrying arbor` and an encircling relief cutter member also carried by said arbor and adapted toM be moved to selected positions of axial Veccentricity relatively thereto and to said first named cutter members. v Y

6. In a breaching tool, the combination, with a carrying arbor, of plurality of circu lar cutter members removably positioned therealong, certain of said cutter members .seing incapable of displacement from positions of coaxality with said carrying arbor, and one of said cutters being adapted to be adjusted to varying positions of eccentricity with respect to the axis of said carrying arbor and of 'said first named cutters, and

means for individually securing said cutters in position on said carrying arbor.

7. A breaching tool, having, in combinatien with a supporting arbor, a coaXially disposed circular breaching member removation.

LOWELL C. BLOMSTROM. e 

